Subject: Re: 630 series.
To: The Great Mr. Kurtz \[David A. Gatwood\] <davagatw@Mars.utm.edU>
From: Scott Reynolds <scottr@og.org>
List: port-mac68k
Date: 11/07/1996 00:47:14
On Wed, 6 Nov 1996, The Great Mr. Kurtz [David A. Gatwood] wrote:

> > 	One other question to whomever wrote the FPU emulation: Will this
> > emulation be affected by the same bug that keeps SoftFPU from working on
> > certain (read: mine) revisions of the 68LC040? If so, am I pretty much out
> > of luck forever when it comes to NetBSD?
> 
> I remember reading about that bug.  I doubt it will affect NetBSD's FPE.
> SoftFPU doesn't actually emulate anything.  It just rewrites the calls,
> converting them from FPU calls to SANE toolbox calls.  NetBSD FPE does
> true emulation and is thus less likely to notice the 68LC040 bug... but
> not guranteed or anything.

Unfortunately, there's a problem with the FPE's handling of postincrement
and predecrement addressing modes on the LC040.  (It wasn't really
coded with this CPU in mind, in the first place.)  I'm not sure if this is
the only problem or not, but it's certainly enough to keep the LC040-based
machines from working properly at the moment.

--scott